Summary ? Core B The Anatomy and non-human primate behavior Core (Core B) will be an essential part of the Udall Center at Emory University. One of the major functions of this Core will be to prepare and process brain tissue from experimental animals generated by the Center projects. This service will be done with standardized histologic techniques, and will provide information that will be indispensable for the interpretation of the functional experiments under projects 1 and 2, and will facilitate sharing and comparisons of results among all three projects. Specifically, the Core will provide the following services: (1) Use of immunohistochemical and microscopy approaches to evaluate the degree of dopaminergic depletion in animals treated with 6- hydroxydopamine (6-OHDA, used in mice in project 1) or 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP, used in monkeys in projects 2 and 3); (2) use of histological markers to delineate nuclei in the motor thalamus in rodents (projects 1) and monkeys (projects 2 and 3); (3) histological reconstructions of recording electrode trajectories (projects 1 and 2); (4) analysis of the degree and pattern of expression of opsins after viral transfection (projects 1 and 2); (5) detection and digital reconstruction of biocytin-filled neurons (project 1); and (6), the cataloguing and storing of brain tissue of MPTP-treated monkeys. A second major service of Core B will be to systemically treat Rhesus monkeys from projects 2 and 3 with the neurotoxin MPTP and evaluate parkinsonism resulting from this treatment with standardized methods. This will allow us to generate animals with similar levels of parkinsonism across both projects, and will facilitate comparisons of data generated by them. By providing these services, the Core will help to free up time and resources from the research projects. In addition, the use of standardized anatomical and behavioral assessment techniques will help us to maintain a consistently high level of quality of Center research.